Alternating-current power-transmitting apparatus.



9- 786,416- PATENTED APR. 4, 1905. H. H. CUTLER.

ALTERNATING CURRENT POWER TRANSMITTING APPARATUS.

APPLIOATION FILED JAN. 28, 1904.

2 SHEE S-SHEET l.

PATENTED APR. 4, 1905.

H. H. CUTLER.

ALTERNATING CURRENT POWER TRANSMITTING APPARATUS.

APPLICATION TILED JAN. 28, 1904.

2 gHEETS-SHEET 2.

UNITED STATES HENRY H. CUTLER, OF

CUTLER-HAMMER MANUFACTURING COMPANY, OF

Patented April 4, 1905.

PATENT OFFICE.

MILWAUKEE, \VISCONSIN, ASSIGNOR TO THE MILIVAUKEE,

WISCONSIN, A CORPORATION OF WISCONSIN.

SPECIFICATION forming part of Letters Patent No. 786,416, dated April4;, 1905. i

1904. Serial No. 190,968.

To (ti/Z 7071/0171. 71/; may concern: I Be it known that I, HENRY H.CUTLER, acitil Zen of the United States, residing at Milwaul kee, in thecounty of Milwaukee and State of Wisconsin, have invented new and usefulImprovements in Alternatinglurrent Power- TransmittingApparatus, ofwhich the followl ing is a full, clear, concise, and exact description,reference being had to the accompanying drawings, forming a part of thisspecification.

My invention relates to improvements in al ternating-power-transmittin gapparatus, my object being to provide means for imposing the load uponan alternating-current motor, either single phase or pol y phase,without causing undue strain upon said motor or upon thepower-transmission system, and to this end I provide a controllablemagnetic clutch interposed between the motor and its load and means forsupplying a current suitable for operating the same.

The present invention is a modification of the apparatus set forth in myapplication filed October 22, 1903, Serial No. 178,117.

The present invention relates more particularly to non-synchronousmotors, and in an application filed by me January 22, 190 1, Serial handside of the drawing. Fig. 2 is a face view of the primary member of myclutch or accelerator. Fig. 3 is a diagrammatic view showing thecircuits employed in connection with a single-phase motor, and Fig. I isa diagrammatic view showing thecireuits employed 1 for a triphase motor.

Like numerals refer to like parts throughout the several figures of thedrawings.

In constructing the preferred embodiment of my invention I provide uponthe shaft 1 of No. 190,145, I have shown means for starting thealternatingcurrent motor 2 a loose pulley 3, which in the presentinstance constitutes the secondary or induced member of a magneticclutch or accelerator, the primary member of which is keyed to theshaft 1. The primary or inducing member of this clutch is constructed inaccordance with the invention of an application filed by me the 5th dayof August, 1903, Serial No. 168,388, and consists, briefly, of a backplate 4, to which is secured a pair of rings 5 and 6, the ring 5carrying inwardly-extemling polar projections and the ring 6 carryingoutwardly-extending polar projections, the two sets of poles beingarranged in overlapping positions, as shown in Fig. 2. The spacesbetween the pole-pieces are filled with non-magnetic material 7, whichmay be Babbitt metal or other equivalent material. Inclosed within theprimary member is the energiZing-winding 8, which is shown of annularform. Due to the particular construction of the primary member of thisclutch, I am enabled to provide a clutch in which the driven member isaccelerated through the combined influence of induction and friction,the induction being to create in the secondary member torqrre-producingcurrents. Due to the fact that the frictional effect is a constant forceduring the period of acceleration and the inductive effect is agradually-decreasing force as the driven member accelerates, it will beseen that I am enabled to provide a clutch in which the driven memberwill be automatically gradually accelerated and will operate without thejar or sudden starting which has been found so objectionable to magneticclutches of the prior art. It is apparent that if just sufficientcurrent is admitted to start the driven member the same will not attainfull speed and can be driven at any desired speed less than the speed ofthe driving member until the current is increased sufliciently to bringthe driven member to full speed. Therefore by controlling the amount ofcurrent which is admitted to the energizing-winding of the clutch I amenabled to provide a clutch which is gradually accelerating and underthe full control of the operator.

The terminals of the winding 8 areconnected, respectively, with thecontact-rings 9 10, upon which rest suitable brushes which serve toconvey the current to the clutchwinding.

Direct current is supplied to the clutchwinding by a direct-currentexciter 11, having a pulley 12, connected bya belt 13 with a pulley 14,mounted upon the shaft 1 of the motor 2, whereby as the motor 2 isoperated the exciter is driven and supplies current to energize thewinding 8 of the clutch.

The clutch is controlled by the regulator 16 and, as shown in Fig. 3, isconnected in circuit with the resistance 17, the sections of which areconnected with the contact-terminals 18, over which the contact-arm 19is adapted to be moved by hand, a retainingmagnet 20 serving to normallyhold the arm in the on position and a coiled spring mounted at the pivotof the lever serving to automatically return the contact-arm to the offposition when the retaining-magnet is deenergized. The clutch-winding 8is supplied with a direct current by the exciter 11, and to this end oneterminal of the exciter is connected by the conductor 21 through theretaining-magnet 20 with the resistance 17. The opposite terminal isconnected by the conductor 22 with one terminal of the clutchwinding 8and the opposite terminal of the clutch-winding is connected byconductor 23 with the contact-arm.

Diagrammatically illustrated in Fig. 3 is the controlling apparatus,which may be used with a single-phase induction-motor having, say, fourfield-coils 20, 21, 22, and 23. I have selected this number of coilsmerely for the purpose of illustration and I have not illustrated therotor or secondary member of the motor, although it will be understoodthat the usual secondary element in a single-phase motor iscontemplated. With the supply-main 24 aresistance 25, subdivided into aplurality of sections, is connected, and likewise a resistance 26,subdivided into a plurality of sections,connected with the terminals 27.Asecond resistance 28 is also employed and is likewise subdivided intosections which are connected with the terminals 29. One of theseresistances-as, for instance, the resistance 26is non-inductive incharacter, while the resistance 28 is inductive in character. Theresistance may be non-inductive and is for thepurpose of reducing thepotential supplied to the field of the motor at starting. A contact-arm30 is provided with a contactbrush connected by conductor 31 through thefield-windings 20 and 21, thence by conductor 32 to terminals 33 and 34,thence across the bridge 35 to terminal 36, thence by conductor 37 tothe opposite main 24 of the supply-circuit.

The contact-arm 30 carries a brush 38, adapted to sweep over terminals29, this brush being connected by conductor 39 with a brush 40, adaptedto sweep over a contact-bar'41, which bar is connected by a conductor 42through the windings 22 and 23, thence by conductor 43 to conductor 37and main 24.

\Vhen the contact-arm 30 has been moved to the extreme position to theright, the brush upon the end thereof engages terminal 45, the brush 38engages terminal 33, and the bridge 35 is moved by means of thecontactarm out of engagement with the terminals 34 and 36. When thecontact-arm is in its full on position, it is held by a retainingmagnet44, which is connected with the terminals of theexciter 11 by conductors47 and 48, respectively, and is supplied with a direct current thereby.

The operation of starting the motor is as follows: The parts beinginitially as shown in Fig. 3, the operator moves the contact-arm 30 tothe right, accordingly cutting out the resistances 26 and 28. Circuit isclosed from the main 24 through the resistance-25, resistance 26,conductor 31, field-windings 20 and 21, conductor 32, terminals 33 and34, across the bridge 35 to terminal 36, and thence by conductor 37 tothe opposite main 24. Circuit is also closed from the main 24 throughthe resistance 25, resistance 28, brush 38, conductor 39, brush 40,contact 41, conductor 42, field-windings 22 and 25, conductors 43 and 37to the opposite main 24. Since the resistance 26 is non-inductive, whilethe resistance 28 is inductive, the current passing through theresistance 28 will be retarded in phase, and accordingly thefield-windings are subjected to current of different phase, whichproduce a rotating magnetic field, thereby starting the armature orsecondary member of the motor. As the contact-arm is moved to the rightto cut out the resistance the armature gradually builds up in speed.While the contact-arm is moved over the series of terminals 27 29 thefields which are thus connected in two parallel paths are subject topractically one-half of the normal voltage of the supply-circuit, due tothe interposition of the resistance 24. hen the contact-arm has beenmoved to the extreme rightthat is, to the full on positionthe bridge 35is moved out of engagement with terminals 34 and 36, and the fields arethereby connected in series, the resistance 25 being at the same timeremoved from the circuit, so that the full voltage of the supply-circuitis imposed upon the circuit containing the field-windings. This circuitmay be traced from the main 24 to the terminal 45, thence by conductor31, through the field-windings 20 and 21, conductor 32, terminal 33,brush 38, conductor 39, brush 40, contact 41, conductor 42,field-windings 22 and 23, conductors 43 and 37 to the opposite main 16of the supply-circuit. The retaming-magnet 44 serves to retain thecontact-arm 30 in the full on position and the current thereto may betraced from one ter- IIO minal of the exciter 11 through the conductor48, through the magnet 44, and thence through the conductor 47 to theopposite terminal of the exciter. The motor is thus brought to fullspeed and operates the exciter 11 to supply a directcurrent to theclutch-winding 8. When it is desired to impose the load on the motor,the contact-arm 19 of the clutchcontrolling resistance is moved to thefirst terminal, and current is thus closed through the clutch-windingswith all the resistance in circuit. The circuit may be traced from oneterminal of the exciter 11 through the conductor 21, the magnet 20,resistance 17, contact-arm 19, and thence through the conductor 23 tothe opposite terminal of the exciter. The secondary member of the clutchis thus started from rest and is accelerated in speed as the resistanceis removed from the circuit of the clutch-winding by moving thecontact-arm 19 to the right. When the resistance has all been removed.from the circuit, the clutch-winding is energized to the maximum extent,and the energization is suflicient to bring the driven part to fullspeed, which has been effected by the motor working at an effectivespeed with relatively high efficiency and power-factor, and theelectrical pressure of the distributing-circuits has not been undulydisturbed. When the contact-arm reaches the full on position, it isgrasped by the retaining-magnet 20 and held in this position duringnormal operation.

If for any reason the secondary supply-cir- .cuit containing theclutch-winding should become broken or if the potential for any reasonshould fall in value, the retaining-magnets 20 and 44 would bedeenergized, and the motor would thus be brought to rest, and thecircuit through the clutch winding would be opened at the controller.When it is desired to shut down the machinery which the motor isdriving, the clutch-winding may be deenergized by moving the contact-arm19 to the off position. The motor continues to run at normal speed; butthe clutch permits the load to be disconnected therefrom. Likewise if itbe desired to operate the driven machinery at less than normal speed thecontact-arm may be moved to a position to insert resistance in serieswith the clutch-winding to energize the same to the desired degree, andthereby produce the desired speed of rotation of the driven member whilethe motor continues to operate at its most effective speed. If it bedesired to shut down the motor, the clutch may be first deenergized bymoving the contact-arm 19 to the off position and then moving thecontact-arm 30 to the off position, or the motor could be shut down, inwhich case the eXciter 11 would stop and the magnet 20 be deenergized,allowing the arm 19 to fly back to its off position.

In Fig. 4 I have illustrated the circuit arrangement for a polyphaseinduction-motor,

the circuit arrangement being designed for a three-phase motor. Thesupply-mains 48, 49, and 50 are connected, respectively, with the posts51, 52, and 53 of a three-blade doublethrow switch. hen thrown in onedirection, the blades engage terminals 57, 58, and 59 and when thrown inthe other direction engage terminals 54, 55, and 56. Resistances 60, 61,and 62 are interposed between the upper set of terminals and the lowerset, so that when the switch is in the up position these resistances areconnected in circuit and when in the down position they are removed fromthe circuit. The field-windings 62, 63, and 64 are connected between theterminals 54, 55, and 56 in the usual manner, as illustrated.

In starting the motor the switch-blades are moved into engagement withthe terminals 57 58, and 59, respectively, and the currents of differentphase which are supplied to the field-windings 62, 63, and 64 arereduced in amount due to the interposition of the resistances 60, 61,and 62. As the armature of the motor rises in speed the switch-bladesare thrown into engagement with the terminals 54, 55, and 56, thusremoving the resistances from circuit and permitting the motor to attainfull speed. An exciter driven by the motor serves to supply a directcurrent to the clutch and also to the retaining-magnet of theclutch-controller, and the load may be applied to the motor after thesame has attained full speed. I In stopping the machinery to be drivenby the motor the motor may be shut down, thus stopping the exciter anddenergizing the clutch, or the controller-arm may be moved to the offposition and the clutch deenergized without stopping the motor.

While I have described the preferred embodiment of my invention, it willbe understood that I do not wish to limit myself to the details ofconstruction, as there are numerous changes which may be made withoutdeparting from the spirit of my invention. The eXciter need notnecessarily be driven by the motor, or it may be driven by powerproduced by the motor in other ways, and the clutch may be associatedvwith the motor in a different manner from that shown and described byme. Moreover, the alternatingcurrent motor and eXciter may be of anytype.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is-

1. The combination with an alternating-current motor, of an inherentlygradually accelerating magnetic clutch associated therewith, and meansfor generating a current for operating said clutch.

2. The combination with an alternating-current motor, of an inherentlygradually accelerating magnetic clutch associated therewith, and meansoperated by said motor for supplying current to said clutch.

3. The combination with an alternating-cur- IIO rent motor, of aninherently gradually accelerating magnetic clutch associated therewith,and an exciter for supplying current to said clutch.

4. The combination with an alternating-current motor, of an inherentlygradually accelerating magnetic clutch associated therewith, and anexciter operated by said motor for supplying current to said clutch.

5. The combination with an alternating-current motor, of an inherentlygradually accelcrating magnetic clutch associated therewith, meansoperated by said motor for supplying current to said clutch, and meansfor controlling said clutch.

6. The combination with an alternating-current motor, of a controllablemagnetic clutch whose driven member is accelerated through the combinedinfluence of induction and friction associated therewith, and means forgenerating a current for operating said clutch.

7. The combination with an alternating-cur rent motor, of a controllablemagnetic clutch whose driven member is accelerated through the combinedinfluence of induction and friction associated therewith, and meansoperated by said motor for supplying current to said clutch.

8. The combination with an alternating-eurrent motor, of a controllablemagnetic clutch whose driven member is accelerated through the combinedinfluence of induction and triction associated therewith, and an exciterfor supplying current to said clutch.

9. The combination with analternating-eurrent motor, of a controllablemagnetic clutch whose driven member is accelerated through the combinedinfluence of induction and frietion associated therewith, and an exciteroperated by said motor for supplying current to said clutch.

10. The combination with an alternatingcurrent motor, of a controllablemagnetic clutch whose driven member is accelerated through the combinedinfluence of induction and friction associated therewith, means operatedby said motor for supplying current to said clutch, and means forcontrolling said clutch.

11. The combination with an alternatingcurrent motor, of a clutch whosetorque-prod ucing power normally decreases as the driven member isaccelerated, means for increasing the torque, and means for generatingthe current for operating said clutch.

12. The combination with an alternatingcurrent motor, of a clutch whosetorque-producing power normally decreases as the driven member isaccelerated, controllable means for increasing said torque, and meansfor generating the current for operating said clutch.

13. The combination with an alternatingcurrent motor, of a clutch whosetorque-producing power normally decreases as the driven member isaccelerated, controllable means for increasing said torque, and meansoperated by said motor for supplying current to said clutch.

14. The combination with an alternatingcurrent motor, of a clutch whosetorque-pro ducin power normally decreases as the driven member isaccelerated, controllable means for increasing said torque, and anexciter for supplying current to said clutch.

15. The combination with an alternatingcurrent motor, of a clutch whosetorque-producing power normally decreases as the driven member isaccelerated, controllable means for increasing said torque, and anexciter operated by said motor for supplying current to said clutch.

16. The combination with an alternatingcurrent motor, of a controllingdevice for starting said motor, a retaining-magnet lor holding theoperative element of said starting device in a prearranged position, andmeans operated by said motor for supplying a current to saidretaining-magnet.

17. The combination with an alternatingcurrent motor, of a controlli ngdevice for starting the same, a retaining-magnet for holding theoperating element of said starting device in a prearranged position, andan exciter for supplying a direct current to said retainingmagnet.

18. The combination with an alternatingcurrent motor, of a controllingdevice 'i OISbZU'lk ing the same, a retaining-magnet for holding theoperating element of said starting device in a prearranged position,andan exciter driven by said motor for supplying a direct current to saidretaining-magnet.

19. The combination with an alternatingcurrent-supply circuit, of amotor associated therewith, a controlling device for starting the same,a magnetic clutch or accelerator associated with said motor, aretaining-magnet for the operating element of said starting device, andan exciter for supplying a direct current to said retaining-magnet andsaid clutch.

20. The combination with an alternatingc'urrentsupply circuit, of amotor associated therewith, a controlling device for starting the same,a magnetic clutch or accelerator associated with said motor, aretaining-magnet for the operating element of said starting device, andan exciter driven by said motor for supplying a direct current to saidretainingmagnet and said clutch.

21. The combination with an alternatingeurrent-supply circuit, of amotor associated therewith, a suitable starting device for said motor, amagnetic clutch or accelerator associated with said motor, astarting-box for said clutch, a retaining-magnet for the operatingelement of said starting-box, and an exciter for supplying a directcurrent to said retaining-magnet and to said clutch.

22. The combination with an alternatingcurrent-supply circuit, of amotor associated therewith, a suitable starting device for said motor, amagnetic clutch or accelerator associated with said motor, astarting-box for said clutch, a retaining-magnet for the operatingelement of said starting-box, and an exciter operated by said motor forsupplying a direct current to said starting-box and said clutch.

23. The combination with an alternatingcurrent-supply circuit, of amotor associated therewith, a suitable starting device for said motor, amagnetic clutch or accelerator associated with said motor, a suitablestarting-box for said clutch, retaining-magnets for the movable elementsof said motor-starting device and said clutch-starting box, andanexciter for supplying a direct current to said retaining-magnets andsaid clutch.

24. The combination with an alternating- HENRY H. CUTLER.

Witnesses F. S. VVILHorr, L. 'D. RoWELL.

